A disabled woman who attacked and decapitated her mother in Sydney's west had the horrific crime "held against her" by the sentencing judge, a court has heard.
WARNING: This story contains graphic content some readers may find upsetting.
Jessica Camilleri was last year jailed for more than 21 years for the "savage" killing of Rita Camilleri, 57, at the family's St Clair home in July 2019.
Camilleri stabbed her mother at least 100 times using seven knives, four of which broke in the frenzy.
She was trialled for murder in the NSW Supreme Court but was found guilty of manslaughter by a jury, after hearing she was substantially impaired.
On Friday, the 28-year-old challenged her sentence in the Court of Criminal Appeal, arguing her "loss of control" in the attack was not properly considered.
Justice Helen Wilson imposed a prison term of 21 years and seven months, with 16 years and two months to be served before Camilleri was eligible for parole.
The maximum sentence for manslaughter is 25 years.
During the sentencing, Justice Wilson acknowledged the "tension" between balancing the need for punishment and sentencing a "significantly disabled offender".
The judge found that despite Camilleri's loss of control, she understood what she was doing and "how very wrong it was".
"The offender's disabilities are such as to attract sympathy; her conduct is such as to attract the strongest condemnation, and punishment," she said.
"In light of the extreme gravity of this crime, the very great harm done, and the need to protect the community from the offender, a stern sentence is called for."
Tim Game SC, for Camilleri, told the court on Friday his client's disabilities were "on the border" of mental illness, and claimed her sentence did not reflect that.
Mr Game said Justice Wilson erred by focusing on how Camilleri understood her actions instead of the fact two psychologists found she experienced a "loss of control for the duration of the attack".
"She did understand that it was very wrong, but that's not the end of the question," Mr Game said.
"You don't start it by saying, 'you're very lucky you've got manslaughter' … and hold it against her."
He also argued Camilleri should have received a greater discount on sentence because she offered to plead guilty to manslaughter before the trial.
"[She had] done everything that she could to bring about the outcome that was achieved as early she could".
Mr Game said there had been a "considerable improvement" in his client's conduct since she was recently moved to another prison.
The Crown is arguing against the appeal, saying Justice Wilson was right to impose a heavy sentence for a "grave" crime.
It claims Camilleri's disability may have been "to her benefit" on sentence, as it may have been the only thing stopping her from receiving the maximum term.
The Crown points to a line in the judgement which illustrates that: "As I observed at the outset, this is as serious an example of manslaughter as it is possible for such a crime to be."
The court has reserved its decision on the appeal and will hand it down at a later date.